Halligan P W, Marshall J C
Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom.
Conscious Cogn. 1998 Sep;7(3):356-80. doi: 10.1006/ccog.1998.0362.
We describe some of the signs and symptoms of left visuo-spatial neglect. This common, severe and often long-lasting impairment is the most striking consequence of right hemisphere brain damage. Patients seem to (over-)attend to the right with subsequent inability to respond to stimuli in contralesional space. We draw particular attention to how patients themselves experience neglect. Furthermore, we show that the neglect patient's loss of awareness of left space is crucial to an understanding of the condition. Even after left space has been brought into the patient's consciousness (either by local cueing on the left or by an emphasis on global properties of the scene as a whole), this awareness of left space rapidly declines. We suggest that much of the symptomology of left neglect can be interpreted as a disconnection between brain mechanisms that are relatively specialized for local (detail) visual processing and global (panoramic) processing. This failure of communication between functional (subpersonal) mechanisms then has consequences for how perceptual and representational content enters into awareness. Failure of the local contents of left space to be consciously accessed is, in turn, an important aspect of why left neglect is so difficult to remediate. Patients can "know" that they have neglect but are cut off from the perceptual awareness that would enable them to overcome their attentional bias to the right.
我们描述了左侧视觉空间忽视的一些体征和症状。这种常见、严重且往往持续时间较长的损伤是右侧半球脑损伤最显著的后果。患者似乎过度关注右侧，随后无法对患侧空间的刺激做出反应。我们特别关注患者自身对忽视的体验。此外，我们表明忽视患者对左侧空间的意识丧失对于理解这种病症至关重要。即使左侧空间已进入患者的意识（要么通过在左侧进行局部提示，要么通过强调整个场景的全局属性），这种对左侧空间的意识也会迅速下降。我们认为，左侧忽视的许多症状可以解释为相对专门用于局部（细节）视觉处理和全局（全景）处理的脑机制之间的脱节。这种功能性（次人格）机制之间的通信失败进而会影响感知和表征内容如何进入意识。左侧空间的局部内容无法被有意识地获取，反过来，这也是左侧忽视难以纠正的一个重要原因。患者可能“知道”自己存在忽视，但却无法获得能够使他们克服对右侧的注意力偏向的感知意识。
